NUT Powersaving features and using outlet collection

Desc: NUT Powersaving features and using outlet collection
File: powersaving.txt
Date: 14 June 2003
Auth: Arnaud Quette

This document introduces NUT PowerSaving features, and Smart
Outlet Management using Network UPS Tools.

This feature is sponsored by MGE UPS SYSTEMS.

Introduction
------------

This feature, which is supported by various manufacturers,
under various names, allows to manage outlets (of an UPS,
and maybe intelligent switch) separately. This allows to
program a limited backup time to non-critical loads in order
to keep the maximum of the battery reserve for critical
equipment.

On small setup, you can plug printers, hubs, (...) on
PowerSave'd outlets. During a power outage, the UPS will
turn off those after X minutes of back-up time (or when
passing below X % of battery charge) depending on your
UPS model and settings, and will ensure that all
remaining battery power is available for the computer.

On huger setup (with a huger UPS), this is about the
same with the ability to (power and) control servers in
a smart way (need to notify those to shutdown first !).

Manufacturers Powersaving technologies presentation
===================================================

1) MGE UPS SYSTEMS
------------------

This feature is called "PowerShare" and is available
on lots of models, with different behaviours.

Features will vary according to your exact model. 
For example:

- on Pulsar Ellipse Premium 650/800/1200, you can
only set a low battery level which triggers a power
off of the PowerShare outlet(s).
Check http://www.mgeups.com/products/pdt230/smallups/ellipsep/ellipsep1.htm

- on Pulsar Evolution (all models), you can either
do the same as above, or set a timer to shutdown
the outlet when expired. This latter needs to be
used in conjonction with upsmon/upssched to act
upon a power outage, and cancel the timer when
the power is back...

2) Other manufacturers (Belkin, ...)

To be completed...


Integration into the new NUT naming scheme
==========================================

Have a look at new-names.txt, "outlet" section.


Note on outlet collection usage
===============================

1) outlet.{id, desc, ...} represents the
whole outlets (includes all outlet.x.*),
also called Main Outlet.

An interesting fact is that _ALL_ models
have at least that outlet, which is always
considered as the UPS itself. Some values
from the "ups" collection are linked to
the outlet.*, ie:
	- outlet.load is mapped from ups.load
	- outlet.delay.* is mapped from ups.delay.*
		
2) Indexes for other outlets begin by 1. So
the first outlet is "outlet.1.*".


Examples of upsc tree
=====================

1) Here is an MGE Evolution tree with the
main and 2 PowerSaving outlets.

...
outlet.0.desc: Main Outlet
outlet.0.id: 0
outlet.0.switchable: 0
outlet.1.autoswitch.charge.low: 0
outlet.1.delay.shutdown: -1
outlet.1.delay.start: -1
outlet.1.desc: PowerShare Outlet 1
outlet.1.id: 1
outlet.1.switch: 1
outlet.1.switchable: 1
outlet.2.autoswitch.charge.low: 0
outlet.2.delay.shutdown: -1
outlet.2.delay.start: -1
outlet.2.desc: PowerShare Outlet 2
outlet.2.id: 2
outlet.2.switch: 1
outlet.2.switchable: 1
...


2) Here is another MGE Ellipse Premium
tree with the main and 1 PowerSaving
outlets.

...
outlet.0.desc: Main Outlet
outlet.0.id: 0
outlet.0.switchable: 0
outlet.1.autoswitch.charge.low: 0
outlet.1.desc: PowerShare Outlet 1
outlet.1.id: 1
outlet.1.switch: 1
outlet.1.switchable: 1
...